Soluble Selectin Levels in Patients with Lung Cancer

Increased expression of selectins has been found on endothelial cells of venules and capillaries in the tumor stroma of non-small cell lung cancer, suggesting their functional role in the process of chemotaxis for tumor cells. The present study was aimed at analyzing the role of both soluble (s)P-selectin and sE-selectin levels in association with clinico-pathological variables in 116 patients with lung cancer, 38 patients with benign diseases and 59 healthy donors. The results obtained showed that sP-selectin and sE-selectin levels were higher in patients with lung cancer compared to normal donors (p<0.02 and p<0.005, respectively). No differences were observed among patients with various benign diseases for both selectins. Increased levels of sP-selectin and sE-selectin were significantly associated with squamous lung cancer at late stages (p<0.05), but not adenocarcinoma. Both sP- and sE-selectin were independently related to the stage of squamous lung cancer by stepwise regression analysis (p<0.02 and p<0.03, respectively), while only sE-selectin was independently related to the presence of distant metastasis in the same histotype (p<0.02). These results suggest that measurement of plasma soluble selectins might represent a useful laboratory parameter in the management of patients with squamous lung cancer.

Placenta Growth Factor is a Survival Factor for Human Malignant Mesothelioma Cells

Placenta growth factor (PlGF) is a key regulator of pathological angiogenesis and its overexpression has been linked to neoplastic progression. To assess whether PlGF could have a role in malignant mesothelioma (MM), we analyzed the expression of PlGF, VEGF, and their cognate receptors (VEGF-R1 and VEGF-R2) and co-receptors (neuropilin-1 and neuropilin-2) in MM cell lines as well as in resected MM tissues, hyperplastic/reactive mesothelium and normal mesothelium. MM cell cultures expressed both ligands and the associated receptors to a variable extent and released different amounts of PlGF. As assessed by immunohistochemistry, PlGF expression was switched on in hyperplastic/reactive compared to normal mesothelium. Moreover, 74 and 94% of MM tissues overexpressed PlGF and VEGF-R1, respectively ( p<0.05 MM vs normal mesothelium). Administration of recombinant PlGF-2 did not elicit a significant stimulation of MM cell growth, while it was associated with a transient phosphorylation of Akt, suggesting that PlGF-2 could activate downstream effectors of proliferative and cytoprotective signals via VEGF-R1 in MM cells. Indeed, the administration of an anti-PlGF antibody was found to cause a significant reduction of MM cell survival. In conclusion, our data demonstrate that, by acting as a survival factor, PlGF can play a role which goes beyond the stimulation of angiogenesis in MM. This evidence could help the rational design of new therapeutic interventions for this aggressive tumor.

The Fermi Gamma-Ray Space Telescope discovers the pulsar in the young galactic supernova remnant CTA 1

Energetic young pulsars and expanding blast waves [supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars.

Gamma-ray bursts: huge explosion in the early Universe

Long gamma-ray bursts (GRBs) are bright flashes of high-energy photons that can last for tens of minutes; they are generally associated with galaxies that have a high rate of star formation and probably arise from the collapsing cores of massive stars, which produce highly relativistic jets (collapsar model). Here we describe gamma- and X-ray observations of the most distant GRB ever observed (GRB 050904): its redshift (z) of 6.29 means that this explosion happened 12.8 billion years ago, corresponding to a time when the Universe was just 890 million years old, close to the reionization era. This means that not only did stars form in this short period of time after the Big Bang, but also that enough time had elapsed for them to evolve and collapse into black holes.

Serum hepatocyte growth factor as a possible indicator of vascular lesions

To investigate the role of human hepatocyte growth factor (hHGF) in vascular lesions associated with endothelial injury, we measured serum hHGF concentrations in subjects with retinal arteriosclerosis, coronary atherosclerosis, or arteriolitis due to Henoch-Schönlein purpura. Individuals with more advanced grades of retinal arteriosclerosis showed higher serum hHGF concentrations [grade 0, 0.053+/-0.005 ng/mL (n = 68); grade 1, 0.144+/-0.022 ng/mL (n = 21; P<0.01 vs. grade 0); grade 2, 0.338+/-0.036 ng/mL (n = 20; P<0.01 vs. grade 0 or 1); grade 3, 0.526+/-0.051 ng/mL (n = 9; P<0.01 vs. grade 0, 1, or 2)]. Patients with active arteriolitis due to Henoch-Schönlein purpura showed higher (P<0.01) serum hHGF concentrations (0.347+/-0.038 ng/mL; n = 14) than those in the remission phase (0.097+/-0.017 ng/mL; n = 19). Mean serum hHGF concentrations were higher in subjects with coronary atherosclerosis than in those without, but a significant overlap in serum hHGF concentrations was found between subjects with and those without coronary atherosclerosis. Serum hHGF may be an indicator of the presence or development of arteriolar lesions.

Increased plasma free tryptophan levels in human cancer: a tumor related effect?

High free tryptophan (F-TRP) plasma levels are found in cancer patients (CP). F-TRP plasma concentrations are affected by the levels of its carrier, albumin (ALB), and free fatty acids (FFA) competing with TRP for ALB binding sites. The lack of correlation between F-TRP, ALB and FFA in CP suggests a tumor-dependent effect on the rise in F-TRP. To verify this hypothesis, F-TRP, ALB and FFA levels were assayed in 12 lung and 16 breast CP susceptible to radical surgery, before and 15 days after surgical removal of the tumor. F-TRP levels significantly decreased after tumor ablation. Since no correlation was found between F-TRP, ALB and FFA variations, it is conceivable that the tumor itself may be responsible for the high F-TRP levels in CP.

PHA and ConA lymphocyte response in normal, hyperplastic and neoplastic human thymus: morphologic and functional correlations

In the present work the in vitro response to PHA and ConA was determined for thymus lymphocytes from normal, hyperplastic, and neoplastic conditions as well as for peripheral blood lymphocytes from normal control donors. Our investigation has revealed these results: (1) lymphocytes from normal thymus are less responsive to both mitogens than lymphocytes from peripheral blood and abnormal thymus. (2) Lymphocytes from thymic benign lymphoid hyperplasia show an increased response only to PHA regardless of the extent of hyperplasia. (3) Lymphocytes from thymic neoplasia display an increased response to both mitogens regardless of the histologic pattern of the tumor studied. (4) Thymic lymphocytes from patients with myasthenia gravis have a mitogenic response higher than that from thymic lymphocytes from nonmyasthenic subjects. (5) In patients with myasthenia gravis, lymphocytes from neoplastic thymus show a response to PHA higher than that observed for lymphocytes from hyperplastic thymus. It seems clear that two conditions maximally enhance mitogenic response of thymus lymphocytes: thymomas and myasthenia.